The present invention relates to the field of photography, and particularly, to a photosensitive material processing apparatus having a roller cam replenishment system.
The processing of photosensitive material involves a series of steps such as developing, bleaching, fixing, washing and drying. These steps lend themselves to mechanization by conveying a continuous web of film or cut sheets of film or photographic paper sequentially through a series of stations or tanks, each one containing a different processing liquid appropriate to the process step at that station.
There are various sizes of photographic film processing apparatuses, i.e., large photofinishing apparatuses and microlabs. A large photofinishing apparatus utilizes tanks that contain approximately 100 liters of each processing solution. A small photofinishing apparatus or microlab utilizes tanks that may contain less than 10 liters of processing solution.
As noted above, during the processing of photosensitive material, the photosensitive material is conveyed through a processor which may contain a series of stations or tanks. As the photosensitive material is processed, the strength of the processing solution is diminished and will eventually become exhausted. To prevent the continual weakening of the processing solution, additional fresh processing solution is added to the processor to replenish the solution. A drawback with conventional replenishment systems is that generally, replenishment is not directly proportional to the amount of processing solution extracted by the photosensitive media.
Further, some replenishment systems, such as the replenishment system described in U.S. Pat. No. 5,353,087 use complicated bellows, pumps and motor drive mechanisms, as well as electronic systems for driving the pump and bellows systems. This adds cost and complexity to the processor. Also, the use of pump and bellows systems increases maintenance requirements for the processor.
The present invention provides for a photographic processor which includes a system that meters an amount of replenishment solution in direct relationship to the amount of photosensitive media passing through the processor. The system of the present invention utilizes a cam in combination with a conveying roller. The cam engages a valve on a dispensing chamber. When the valve is opened, an amount of processing solution is metered out in response to the amount that the conveying roller is rotated. Thus, a longer piece of media will get more replenishment and vise versa.
The system of the present invention not only drives media but replenishes at the same time. Also, the system of the present invention will replenish only what the media extracts and eliminates the use of bellows pumps, drive motors and associated electronics. Further, the system of the present invention will replenish when the drive is active.
Therefore, the present invention relates to a processor for processing photosensitive media. The processor comprises a processing channel through which a photosensitive media is passed. The processing channel contains processing solution for application to the photosensitive media passing therethrough. The processor further includes a replenishment system that is adapted to replenish the processing solution in the processing channel. The replenishment system comprises a chamber that holds a processing solution and a dispensing mechanism that dispenses the processing solution from the chamber in direct relationship with an amount of the photosensitive media passing through the processing channel. The processing channel is preferably a narrow processing channel in a low volume processor.
The present invention further relates to a method of processing photosensitive media. The method comprises passing a photosensitive media to be processed through a processing channel which contains processing solution for application to the photosensitive media; and replenishing the processing solution in the processing channel by dispensing processing solution into the processing channel in direct relationship with an amount of the photosensitive media passing through the processing channel.
The present invention further relates to a replenishment system for a photographic processor. The replenishment system comprises a chamber for holding a processing solution therein and a dispensing mechanism which dispenses the processing solution from the chamber in direct relationship with an amount of photosensitive media being processed in a photographic processor.
The present invention further relates to a replenishment system for a photographic processor which comprises a chamber which holds a processing solution therein; and a dispensing mechanism which dispenses the processing solution from the chamber. The dispensing mechanism comprises a valve which has a surface that engages a cam roller. The cam roller is operationally connected to a conveying roller of a photographic processor so as to rotate together with the conveying roller, such that a rotation of the cam roller by way of a rotation of the conveying roller causes a movement of the valve between a closed position and an open position. In the open position of the valve, processing solution is dispensed from the chamber to the photographic processor.